This book offers an archaeological study on China's ancient capitals. Using abundant illustrations of ancient capital sites, it verifies the archaeological discoveries with documentary records. The author introduces the dynamical interpretation of each ancient capital to the interpretation of the entire development history of China's ancient capitals. The book points out that for most of the almost 2000 years from the earliest Erlitou ( )to the Ye city ( ), there was an era where ancient capitals didn't have outer enclosures due to factors such as the strong national power, the military and diplomatic advantage, the complexity of the residents, and the natural conditions. Thus an era of "the huge ancient capitals without guards" lasting for over 1000 years formed. The concept that "China's ancient capitals don't have outer enclosures" presented in the book questions the traditional view that "every settlement has walled enclosures". Combining science with theory, it offers researchers of history a clear understanding of the development process of China's ancient capitals.